Variable-speed mechanism.



- A. G. MATHER. VARIABLE SPEED MECHANISM.

A'PPLIGATION FILED JAN. 20. 1909.

Patented July 20, 1909.

unrrsn STATEs ratrsn'r orrron ALLAN G. MATHER, OFOT'li-KWAQONTARIO;CANADA.

VARIABLE-SPEEID MECHANISM.

Specification of Letters Patent.

Patented Jul 20, 1909.

Application filed January 20,1909 I Serial No. $73,247.

To all whom it may concern:

Belt known that I, ALLAN :hIATHER, a

,citizen -of the United States, residing at Ottawa, in the county ofCarleton, Province of Ontario, in the Dominion of Canada, have inventedcertain new and useful Imrovements in Variable-Speed h'iechanisms, ofwhich the following is a specification, reference being had to theaccompanying drawmgs.v

mechanism for, rotating members.

" Theobject of the invention is to provide anew simple and'durabledevice. whereby the speed of a. rotating member can" be set atanyIdesired rate until it reaches a maximum limit determined by thespeed ofrotati'onof the driving surface. Compressed air or. any othersuitable controlling medium can be employed. The invention consists ofa. friction pulley loosely mounted on a shaft, friction shoes carryingpistons adapted to term a frictional contact tion shoes and saidpulley;-a plurality of cylinde'rs,- securely mountedon said shaft, and

4s p k g,

some the shaft upon loosely mounted. having rim formingthe frictionsurfa'ce'adapted to the friction shoes herelnafter.

in the center of ducts for'conveying pressure "to said pistons, whichpressure may be adjustedv by any suitable differential valve" toregulate the speed determin'ed- In'the drawings tion of the machine Fig.2 isa end elevation in part 'sectioiif Referring tofthe drawings inwhich like numerals for reference indicate corresponding. parts .in-eachfigure, -5 indicate bearing boxes 'of any suitable material,-6-reprewhich the pulley 7. is the outer face of its the action ofdescribed.

8 are frictionshoes bearing on'the face of "the pulley 7 and providedwith pistons 9, having cup leathers 10 or other suitable to preventleakage, carried in cylinders 11 which. are formed in the ends. ofspider 12, keyed or otherwise shaft 6, 13' is a bolt screwed into theshoes 8 the piston 9, 14 is a bolt retracting spring held in position bythe bolt 13 and the surrounding thimble I5, screwed into the cylinder11, the cap 16 covers the opening and prevents leakage from the cyl'iu'der.

The invention relates to speed changing corresponding to between saidfric I i tend to slip -shoes-will decrease and 111'C0111b1H2lfiO11 withFigure l is a s ide elevafastened to the.

' IT is a shoulderon the piston for limiting thetra'vel of the friction,"hoes 8.'f|.'om the face of the pulley 7. a

The shaft (5 is drilled centrally at It) to a point where it reaches theduct 18, which in turn communicates with the rear end of the cylinder11.

shaft 6 to receive the tube 23, and is further connected through asuitable stuffing box 20,

with the pressure regulator 21, a1'ul-stop cook 22, compressed air orother suitable means is supplied to the mechanism from any convenientsource through the tube 23. it will thus be readily seen .that whenpressure is adm'tted through the. cock and regulator 21, it will act on.the pistons 9 in the cylinder 11 and press the friction shoes 8 againstthe surface 7, with a force the pressure at which the regulator 21 isset and thus determine the speed of rotationofthelpulley 25 fastened tothe shaft 6. If the resistance overcome,

25 is increasedand the shoes 8 thecentrifugal forceof the by the pulleythe pressure in the cylinders bring the shaft back to the normal rate ofrevolutions for which it is set. The cock 22 is provided with an opening26, so pressure is removed from the cylinders and the shoes 8 are drawnout ofcontact with the face '1 and all rubbing contact thus avoided. 2ais the driving pulley fixedl 'niounted on the hub of the frictionsurface. It: will also be apparent from the foregoing description thatthe speed of the machine The hole 19 is tapped in the 7 thatwhen it isclosed all may be varied without stoppingth'e machine v and may be keptat such varied speed by the regulation of the air pressure by means'ofthe regulator 21.

a-pulley loosely mounted thereon, a spider a shaft,

' regulator and a stop cock, means-circulating fixedly'lnountecl on saidshaft, a plurality tl'lrough sz id passageslz'uid (lu'cts cent-rolled '1J of shoes at the end of said spider, said shoes by said regulator, toeflect an engagement if) provided with pistons carried in cylinders,between the shoes and the pulley. v r ducts. for cenveylng p 'essure tosend cyhn- I ALLAN G. BIATHER I (lGIS through the arms of the spider,and! I connnunicating-thrdugh a suitable passage (h'illedin the shaftwith-a tube having a l Witnesses:

- W. T. CUFFI I-QUIN,

HUGH J. DUNN.

